β受体阻滞剂对心力衰竭大鼠模型心肌纤维化的影响

目的 探讨不同β受体阻滞剂对心力衰竭大鼠模型心肌纤维化的影响.方法 取Sprague-Dawley雄性大鼠,采用结扎前降支方法建立慢性心力衰竭模型.将存活动物随机分组为心力衰竭组(n=9)、卡维地洛组(n=10)、美托洛尔组a=8),并建立假手术模型(n=10),观察各试验组动物的血液动力学变化,进行心肌纤维化的相关指标测定.结果 与心力衰竭组[(4.7±2.5)mm Hg,1 mm Hg=0.133 kPa]比较,美托洛尔组[(3.9±3.0)mm Hg]、卡维地洛组[(4.0±2.6)mm Hg]心肌梗死后左心室舒张末压水平显著低,美托洛尔、卡维地洛改善左心室±dp/dt(P＜0.05).心力衰竭组羟脯氨酸水平[(4.9±2.6)mg/g]明显高于假手术组[(2.5±1.0)mg/g]及卡维地洛组[(2.8±1.8)mg/g],P＜0.05.卡维地洛组羟脯氨酸水平明显低于美托洛尔组[(4.6±2.3)mg/g],P＜0.05.心力衰竭组心肌间质胶原容积百分数、血管周围胶原面积/冠状动脉腔横断面积(PCVA/VLCA)明显高于假手术组及卡维地洛组(P＜0.05).卡维地洛组PCVA/VLCA(3.9±1.2)明显低于美托洛尔组(5.1±1.7),P＜0.05.结论 卡维地洛组胶原含量低于美托洛尔组,提示卡维地洛较美托洛尔有更强的抑制心肌梗死后心肌纤维化的作用.

Effects of carvedilol and metoprolol on cardiac fibrosis in rats with experimental myocardial infarction

Objective To investigate the effects of carvedilol and metoprolol on cardiac fibrosis in rats with experimental myocardial infarction(MI).Methods MI was induced in male Sprague-Dawley rats serve as control.Collagen perivascular circumferential collagen area(PCVA),peri-coronary circumferential collagen area (VLCA) and interstitial collagen volume fraction (ICVF) as well as myocardial hydroxyproline content were determined after hemodynamic measurements at the study end.Results LVEDP were significantly lower and ±dp/dt significantly higher in carvedilol and metoprolol treated MI rats than that in saline treated MI rats.Myocardial hydroxyproline,PCVA/VLCA ratio and ICVF were significantly reduced in metoprolol,more significantly reduced in carvedilol treated MI rats compared to saline treated MI rats (all P＜0.05).Conclusion Metoprolol and carvedilol could decrease the concentration of hydroxyproline and ICVF in MI rats.